Suspended liquid of nano TiO2 and SiO2-Ag for antibacterial finishing

With special performance of nanometer materials, nanometer antibacterial agents are better than usual antibacterial agents. Nano TiO2 (Anatase) and nano SiO2-Ag are just cases in point. Because the nano-powder does not dissolve in water and lacks affinity to the natural fabric, it is necessary to confect the nano-powder into relatively stable suspended liquid and then the nano-powder is transferred into the fabric by pad-roll. Therefore, the effects of dispersant on dispersion of nano TiO2 and SiO2-Ag particles were investigated respectively in this paper. The sedimentation height and the size distribution of the dispersed particles in aqueous solution were employed to characterize the particles dispersion. The experimental results show that sodium hexametaphosphate is efficient dispersant for TiO2 and SiO2-Ag particles in aqueous solution. The zeta potential of the particles in aqueous solution was measured to analyse the dispersion mechanism. Optimal formula for the suspended liquid of the mixed nano-powder TiO2 and SiO2-Ag was obtained by the orthogonal experiments on the ratio of the mixture, the dosage of dispersant and PH value. The antibacterial rate of the finished fabric is shown as follows: the anti-E.coli rate is 100% and the anti-MSSA rate is 96.1% in 5 minutes.